1. Field of the Invention
The invention relates to a projector module, more particularly to a miniature projector module for application to handheld electronic devices.
2. Description of the Related Art
As shown in FIG. 1, in Taiwanese patent no. 232995, there is disclosed a mobile phone that is equipped with a conventional miniature projector module 1. The conventional miniature projector module 1 includes a semiconductor light source unit 11, a polarization beam splitter 12, a reflective image modulator 13, and a projector lens 14.
The light source unit 11 is capable of emitting red, green and blue source light with first and second polarizations in sequence. The polarization beam splitter 12 is capable of reflecting the source light with the first polarization, and permits transmission of the source light with the second polarization therethrough. The reflective image modulator 13 is disposed to receive and convert the source light with the first polarization reflected by the polarization beam splitter 12 into image light with the second polarization, and directs the image light with the second polarization toward the polarization beam splitter 12 for further transmission therethrough. The projector lens 14 is disposed to receive and project the image light with the second polarization from the polarization beam splitter 12.
The main drawback of the conventional miniature projector module 1 is that only the source light with the first polarization is utilized for image projection, and the source light with the second polarization is wasted. In other words, approximately half of the source light is lost, resulting in a reduction in the brightness of projected images.